Key issue is where the mount bolts to the block - is the hole spacing the same. If it is then almost certainly there will be a factory mount for 200 engine/300 chassis and 300 engine/200 chassis
Having a 3.9 disco pre update and gone through issues with the changeover, talking to others etc. Parts (including RRC parts) were been run out/bodged/what was on shelf etc. Parts book is not entirely accurate and also shows overlapping part nos/vin range

